7. (a) Ethanol can be produced by the fermentation of glucose solution - Edexcel - GCSE Chemistry - Question 7 - 2020 - Paper 1
Question 7
7. (a) Ethanol can be produced by the fermentation of glucose solution.
Which of these shows the word equation for the fermentation of glucose solution?
A glucose ... show full transcript
Worked Solution & Example Answer:7. (a) Ethanol can be produced by the fermentation of glucose solution - Edexcel - GCSE Chemistry - Question 7 - 2020 - Paper 1
Step 1
Which of these shows the word equation for the fermentation of glucose solution?
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Answer
The correct answer is B: glucose → ethanol + carbon dioxide. This is because during fermentation, glucose is converted into ethanol and carbon dioxide, with water not being produced in this equation.
Step 2
Suggest the formula of a molecule of pentanol.
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Answer
The formula for a molecule of pentanol, which contains five carbon atoms, is C₅H₁₁OH.
Step 3
Draw the structure of a molecule of ethanol. Show all bonds.
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Answer
The structure of ethanol (C₂H₅OH) can be represented as follows:
H H
| |
H - C - C - O - H
| |
H H
This diagram shows the bonds between the carbon, hydrogen, and hydroxyl groups.
Step 4
Complete the equation for this reaction.
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Answer
The complete equation is:
CH3CH2OH+O2→CH3COOH+H2O
This indicates that ethanol reacts with oxygen to form ethanoic acid and water.
Step 5
Which calculation shows the percentage by mass of hydrogen in ethanoic acid?
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Answer
The correct option is C: ( \frac{4}{60} \times 100 ). This is because there are four hydrogen atoms in ethanoic acid (CH₃COOH), and the total molecular weight is 60.
Step 6
Discuss the reasons for using these polymers in the ways shown in Figure 13 and the problems in disposing of these.
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Polymers are widely used due to their specific properties:
Poly(ethene) is used for plastic bags and bottles due to its flexibility, waterproof nature, and light weight.
Poly(chloroethene) (PVC) is chosen for window frames and pipes because it is tough, long-lasting, and waterproof.
Poly(tetrafluoroethene) (PTFE) is preferred for frying pans as it provides a non-stick surface and high resistance to heat.
However, the disposal of these polymers poses challenges:
They are typically non-biodegradable, leading to environmental concerns, as they can persist in landfills for long periods.
Recycling processes are time-consuming and require significant resources.
Burning these materials can release toxic substances, contributing to air pollution and environmental damage.
